Mathias developed a flexible client uploadFile API for the instantdb/instant repository, enabling direct ingestion of data as either File or Blob objects. He approached the task by updating TypeScript typings to support both input types while maintaining backward compatibility, and revised the README to document the new usage patterns. The implementation leveraged JavaScript and TypeScript, with a focus on seamless API integration and frontend development. By supporting Blob-based uploads, Mathias reduced friction for diverse data sources and laid the foundation for broader file workflows. All changes were tested, documented, and aligned with the project roadmap, reflecting careful, targeted engineering work.